Closure plug



May 12, 1953 J, -r 2,638,242

CLOSURE PLUG Filed Jan. 2, 1951 INVENTOR. xQoe/v J 560// ATTORNEK Patented May 12, 1953 UNITED STATES PATENT CLOSURE PIJUG now-r 1.. Scott, Blue Springs; Mon. assignon to: John G. Hockery,,Kansas Gity,.Mo.,..trustec ApplibatibnJanual'y 2, 1951,.Serial No. 203,911

(Cli. 2201-44 )1 5. Claims; 1

This invention relates in general to closures for pressure vessels; and it' deals more particularly' with a closure plug for the filler opening of the boiler of a steam iron.

Broadly speaking, it is animportant object of the inventionto providea closure for the filler opening of a steam generator or boiler; which closure will effectively seal the opening and prevent the escape of steam therethrough under normal operating conditions.

Another object is to provide aclosure. plug which, while sealing the filler opening under normal pressures, will allow the relief of steam therethrough at excessively high pressures.

further object is to provide a. plug of the character indicated, which isvery simple in design. and economical to manufacture, yet foolproof and" highly" effective in: operation.

Other and further objects ofthe invention, togather with the features of novelty'whereby the obiectsare achieved, will appear in the course of the following description.

Ihthe" accompanying drawings, which form a part of the specification and are to: be read in conjunction therewith, and in which like reference numeralsare employed to identify like parts of the various views:

Fig. 1 is a plan viewof a steam iron embodylng, my invention, showing the location of the closureplug for a filler opening located in the upper" surface of-the boiler, I

Fig. 2 is an enlarged elevational view of a closureplug constructed inaccordance with the invention,

Fig; 3 is a cross sectional view taken along the line 3-.3-cfFig. 2- in the direction ofthe arrows,

Figj l is a sectional view'tak'en along theline 1 of Fig. 1 in the direction of the arrows, showing the filler opening and my closure plug inthe position it occupies under normal operating conditions, and

Fig. 5- is a view corresponding to Fig. 4 but showingthe-plug in the position it occupies when thepressure in the boiler exceeds a predetermi ned'value'.

Referring more particularly to the drawings, the numeral l0 designates the boiler of a convention'al steam iron. In the upper wall of the boiler on one side of the handle H is a circular filler opening adapted to receive my closure plug l2, and, as may best be seen in Figs. 4 and 5, this opening has an annular neck It pressed from themetal of the-boiler shell so that it projects into i the boiler a short distance.

M-ypl'ug, whichcanbe molded of phenolic resichain 2t.

nous material or the like, has at its upper end an enlarged head or knob It, the rim. thereof preferably being serrated, knurled-- or grooved at circumferentiall'yspaced intervals; as shown,v in order to facilitate gripping same with the fingers. Below the head, the plug has a short sec.- tion IT of reduced diameter, this being separatied from the head by a shoulder I8 below the section H" and separated from it: by a second shoulder 2i] is a longenstemsectiOn of 'stilliismaller diameter. The head of the plug; that is: to say, the portion above shoulder lli; is larger than the inside diameter of neck it so. that. it cannot enter the-filler opening, but the next. lower section (l-l) will" enter the opening readily with considerable clearance around i same. as? may readily be appreciated. from Figs. 4 and 5.

A washer 22, which is of approximately the same diameter as section l l, is secured to the bottom of the plug bya screw 25, this screw also serving to securetothe' plug one end of a ball The other end of thechain is connected-to ananchorlink or bar 28 by meansof a loop or eye to atthe middle thereof; it: being understood that the length of the bar is somewhat more than double the diameter of the filler opening.

Between shoulder- 20 and washer 22, the stem ofthe plug is encircledv by'an O-ring 30 of resili'ent gasket material. Referring to Fig. 4, it will be seen that the axial distance between shoulder 2i} and the upper face of washer 22" is substantially double the cross sectional diameter of the gasket,.so that the gasket may'slide or roll up and down on the stem ofthe plug a distance approximately equal to itsown diameter. Thestem of the plugisfiuted as shown at 32, the individual flutes extending upwardlyirom the washer and terminating in shoulders 34 spaced approximately midway between shoulder 20' and Washer- 22";

Inausing my plug, bar 28 first-ispassed' axially through neck M of the filler opening into: the boiler and is allowed to drop trees therein; whereupon, due" to its central suspension. on: chain 26, it will assume a generally horizontal position; in" other words", it will be: crosswise. of. the. opening and will span same so that plug l2 can: be allowed to hang on chain 23 outsideof the boiler while water is being poured intothe boiler through the filler opening;

When the" boiler has been filled to the desired level, plug-'12 is advanced downwardly toward the filler opening allowing the" balance=- of chain 26 to descend into the boiler. As thelowerend of the plug is pushed into the filler opening, (the plug preferably being turned slowly about its own axis at the same time) the outer margin of the gasket ring 30 engages the inner wall of neck I4, and, since the gasket is slightly oversize relative the inside diameter of the neck, it resists movement into the opening sufficiently to insure that the stem of the plug will advance through the gasket until shoulder 20 abuts the upper surface of the gasket; the gasket then must advance with the plug which is halted when shoulder l8 strikes the surface of the boiler about the margin of the opening. As will be seen from Fig. 4,, the gasket now is compressed slightly between the neck l4 and the unfluted upper portion of the stem of the plug so that it forms a suitable seal for the filler opening.

The parts will remain in this position so long as the steam pressure within the boiler remains within the normal operating range. sometimes happens in the normal use of a steam iron that the steam discharge passageway from the boiler becomes clogged, or for some other reason the steam pressure in the boiler becomes excessive. This pressure, of course, is exerted on the plug, and, unless somehow relieved, will blow the plug out of the filler opening with explosive force, or, alternatively, may burst the boiler, either of which represents a source of possibly serious injury to the operator. If the steam pressure rises above an undesirable level when my plug is used, the plug will move outwardly under its influence, but gasket 39 will remain substantially in its normal position due to its frictional engagement with the inner wall of neck l4. Thus when the plug reaches the position shown in Fig.

5, the gasket is disposed over the fluted portion of the stem, and the steam can escape harmlessly through the passageways provided by the fluting as indicated by the arrows, relieving the pressure and consequently halting the outward movement of the plug. The escaping steam is deflected laterally by shoulder [8 so that there is no concentrated discharge of the steam in any particular area.

Thus it will be seen that my plug embodies in a unitary structure a closure which effectively seals the filler opening of the steam iron boiler under normal operating conditions, but also serves as a relief valve for the boiler at undesirably high pressures. The plug may be easily inserted into the aperture or removed when desired to allow filling of the boiler. At the same time, th guard chain and anchor link prevents loss or 1 splacement of the plug when it is removed irom the filler opening. It may readily be appreciated that my unit is of durable construction, simple in design, and very economical to manufacture.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinbefore set forth, together with other advantages which are obvious and which are inherent to the structure.

It will be understood that certain features and subcombinations are of utility, and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the appended claims.

Inasmuch as various possible modifications may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

However, it

Having thus described my invention, I claim:'

1. A closure for an opening in a pressure vessel, comprising a plug having a stem smaller in size than said opening and insertable therein, an annular gasket encircling said stem and bridging the space between the outside of the stem and the confronting annular wall of the opening, said stem movable axially relative to said gasket in and out of said opening, inner and outer stop shoulders limiting the extent of such relative movement, said stem having in its peripheral surface an axial groove terminating at one end adjacent said inner shoulder and terminating at the other end at a point intermediate the two stop shoulders, said gasket engaging the ungrooved. exterior of said stem outwardly from said point when it is positioned against said outer shoulder thereby to form a seal between said stem and the confronting annular wall of said opening, said gasket overlying said groove when it is positioned against said inner shoulder, and the length of said groove in an axial direction being greater than the thickness of the gasket in that direction, whereby the ends of said groove are exposed on either side of said gasket when the latter is positioned midway between the ends of the groove.

2. A closure for an opening in a pressure vessel, comprising a plug having a stem smaller in size than said opening and insertable therein, an annular gasket encircling said stem and bridging the space between the outside of the stem and the confronting annular wall of the opening, said stem movable axially relative to said asket in and out of said opening, inner and outer stop shoulders limiting the extent of such relative movement, said stem being fluted, the fluting extending from said inner shoulder outwardly to a point intermediate the two stop shoulders and underlying said gasket when same is against said inner shoulder, said gasket engaging the ungrooved exterior of said stem outwardly from said point when it is positioned against said outer shoulder therebyto form a seal between the exterior of the stem and the confronting annular wall of said opening, and the ends of said fiuting being exposed on either side of said gasket when it is positioned medially of the fluting thereby to form a flow passageway past the gasket.

3. A closure for an opening in a pressure vessel, comprising a plug having a stem smaller in size than said opening and insertable therein, an annular gasket encircling said stem and adapted to engage the marginal wall of the opening, said gasket movable axially of said stem, stop shoulders limiting the axial travel of said gasket on said stem in each direction, the peripheral surface of the stem containing an axial groove between said shoulders, said groove being of such length that when the gasket is disposed medially of the groove, the opposite ends of the groove are exposed on either side of the gasket, and at least one of said shoulders being spaced beyond the end of said groove by such a distance that when said gasket is against said one shoulder it is in sealing engagement with the ungrooved peripheral wall of said stem beyond the end of the groove.

4. A closure for an opening in a pressure vessel, comprising a plug having a stem smaller in size than said opening and insertable therein, an annular gasket encircling said stem and adapted to engage the marginal wall of the opening, said gasket movable axially of the stem, stop shoulders limiting the axial travel of said gasket on said stem in each direction, the peripheral surface of the stem containing an axial groove between said shoulders, said groove being of such length that when the gasket is disposed medially of the groove the opposite ends of the groove are exposed on either side of the gasket, and the outer one of said shoulders being spaced beyond the end of said groove by such a distance that when said gasket is against said outer shoulder it is in sealing engagement with the ungrooved peripheral wall of said stem beyond the outer end of the groove.

5. A closure as in claim 4 wherein said plug has adjacent said stem a stop shoulder extending radially beyond the edge of said opening to limit the advance of the stem into said opening.

ROBERT J. SCOTT.

References Cited in the file of this patent UNITED STATES PATENTS a Number 2,369,007 2,564,232

Number 240,346 464,534 820,444 

